Managing director of tax advisory firm Taxand UK, Jonathan Hornby, told The Wall Street Journal the new tax may violate existing tax treaties. Specifically, he mentioned treaties that aim to protect multinational corporations from being taxed on the same profits in more than one country.

Only companies with revenues above $15.5 million would be subject to the proposed law.

Political analysts say the new British tax is viewed primarily as a way to target massive U.S.-based companies such as Amazon, Google and Facebook.

The U.S. ambassador to Britain, Mathew Barzun, said multinationals may be efficient managers of their tax liabilities but that they follow the law.